This invention relates generally to a manually actuated pump dispenser having an improved discharge valve member, and more particularly to such a valve member of elastomeric material having a generally conical valve element and a non-reentrant element permitting the discharge valve to be snapped in place on assembly.
The known manually actuator pump dispensers especially those designed for the dispensing of hand lotions, body lotions, liquid soaps, and other more highly viscous products, typically have both inlet and outlet ball check valves for respectively controlling the flow of liquid product into the pump chamber on each piston suction stroke and for controlling the out flow of the liquid product from the pump chamber during each piston compression stroke. The discharge passage immediately downstream of the discharge valve traverses into a discharge extending through an elongated discharge spout. U.S. Pat. No. 4,286,736 is exemplary of such a known pump dispenser.
The difficulty with the discharge valve in the form of a ball check valve is that the creamy product being dispensed oftentimes impedes the full and proper reclosing of the ball check valve against its valve seat on each piston suction stroke following ensuing piston pressure strokes. This is especially a drawback when dispensing more highly viscous liquid products, such as a commercial cleaning gel containing pumice as a scrubbing agent. The passage downstream of the discharge valve retains product being dispensed during the closing of the discharge such that while the ball check valve is out of sealing engagement with its valve seat during the discharge open condition, the viscous liquid product in the vicinity of the valve may interfere with the reclosing of the valve against its seat in a sufficiently quick manner and in a tightly sealed manner for closing the discharge during the piston suction stroke. This could interfere with the smooth and accurate operation expected for the pump.
There is thus the need to improve upon the discharge valving for manual pump dispensers of the aforedescribed type, such that the discharge valve quickly and accurately and sealingly responds to each piston suction stroke by sealing tightly against its valve seat without delay. Such a valve must also be capable of easy and uncomplicated sub-assembly with other parts of the pump while at the same time be economical to mass produce yet highly reliable.
It is therefore an object of the present invention to provide an improved discharge valve member for a manual pump dispenser which will quickly respond for sealing the discharge flow path during each piston suction stroke irrespective of the viscosity of the product being dispensed, while at the same time is economical to mass produce and yet highly reliable and efficient in operation and easy to assemble. The improved discharge valve member according to the invention is an elastomeric valve having a conically shaped valve element and a non-reentrant portion permitting the valve to be snap-fitted into place within the pump body. The conical valve slopes outwardly in a downstream direction and its outer conical surface engages a conical valve seat defined within the pump body presenting a tight seal in the discharge closed position.
The non-reentrant portion of the valve snap fits within an opening of a transverse web within the pump body, such wall being spaced axially from the valve seat a predetermined distance so as to effect the tight sea of the conical valve element against its seat.
Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description of the invention when taken in conjunction with the accompanying drawings.